ABSTRACT
Aquifers near uranium mines may be contaminated with uranium and other metals. Under certain conditions, indigenous microbes can be used to clean up the groundwater. In this case, the microbes control chemical and bio-geochemical reactions such as adsorption, precipitation, and immobilization of radioactive and hazardous metals. In the present study we have selected groundwater from the site of the former uranium mine at Königstein, Saxony, Germany. The mine will be flooded in the near future. The flooding water (termed G4) will be contaminated with uranium and heavy metals. The pH will be <3 because uranium was mined by acid leaching of the sandstone host rock. Fractions of the contaminated water may leak into an adjacent freshwater aquifer (termed G3). In this event, the G3 aquifer must be decontaminated. The depth of about 200 m below the surface prevents construction of a permeable barrier. Conventional pump-and-treat is traditionally the most expensive and least reliable process. Therefore, in situ bioremediation has been considered.
